San Rafael Bay environmental work captured in book

Environmental work by a Tiburon-based researcher in the shallows of San Rafael Bay to protect the shorelines has been documented in a new book.

As part of the project in the bay that began in 2013, small oysters have grown by the millions as part of the state Coastal Conservancy’s Living Shoreline Project. The term “living shorelines” refers to providing space for plants and animals as a key part of coastal protection, according to the conservancy.

As part of the work, crews built and dropped reefs — made of oyster shells from the now shuttered Drakes Bay Oyster Co. — about 600 feet offshore into San Rafael Bay near Starkweather Park. Since then the Olympia oysters, and other associated creatures, have turned up.

The book, “Living Shorelines: The Science and Management of Nature-Based Coastal Protection,” details that work. The book is the first to compile, synthesize and interpret the science and practice of nature-based shoreline protection, according to the state Coastal Conservancy.

“Our work in the bay is a terrific example of living shoreline concepts put into practice,” said Kathy Boyer, professor of biology at San Francisco State University’s Romberg Tiburon Center for Environmental Studies, who led the work noted in the book. “We explain the importance of the data we’re collecting for maintaining healthy subtidal habitats and we give clear, practical instructions for creating a sustainable living shoreline.”

The Living Shoreline Project is designed to stabilize banks and restore habitats to strengthen shorelines and minimize erosion, which helps maintain coastal ecosystems and protects and restores habitat for fish, aquatic plants and wildlife.

“Living shorelines are an innovative new approach to climate adaptation and shoreline management,” said Marilyn Latta, project manager for the coastal conservancy, the lead agency on the project. “We planted eelgrass and deployed artificial reefs for native oysters, which provide habitat as well as food for a variety of fish and bird species.”

Specifically in San Rafael Bay, it was the Olympia oyster, which measures no more than 1.5 inches in diameter when fully grown, that the project helped bring back. Once plentiful in the bay, the oyster acts as a water purifier, as well as habitat and food for a variety of fish species.

Overharvesting and pollution helped diminish oyster numbers in the 19th and 20th centuries, while sediment and development in the bay eliminated hard surfaces on which the oysters need to grow.

One of its key functions is its ability to act as a mini-filter. Although small, they can take in large quantities of sea water — as much as 20 to 30 quarts an hour — and extract pollutants and algae-causing plankton.

As it turned out, the San Rafael shoreline was the perfect place to try to re-energize the species. The shallow water made the locale ideal. Researchers could walk into the bay to the site to examine the reefs.

In addition to seeing oysters flourish, there have been ancillary benefits for other species. Crabs along with shrimp and other invertebrates have turned up on the reefs. The black oystercatcher, which breeds on the nearby Marin Islands, has been spotted along the shore where it had not been seen for some time.

“It’s revitalized the coastal ecosystem, brought new seabirds and wildlife to these areas, and we are testing concepts that can be scaled up to protect communities from sea level rise by creating a natural buffer between land and sea,” Latta said.